Hydraulic pump



NOV. 16, 1948. OHARAH 2,453,929

HYDRAULI C PUMP Filed March 11, 1947 '1 FIG. 2

INVENTOR ALVIN F. OHARAH ATTORNEY Patented Nov. 16,1948

'um'ro "STATES PATENT OFFICE HYDRAULIC PUIMP Alvin F. OHarah, Erie, Pa.Application March 11, 1947, Serial No. 733,793

1 Claim.

This invention relates to fluid pumps generally, and is moreparticularly directed to improvements in pumps of the hydraulicallyactuated character.

An important object of the invention resides in the arrangement of aninexpensive and relatively simple hydraulically actuated fluid pumpwhich is not limited as to size or fluid pumping capacity and may beapplied to the pumping of fluid from deep wells or wherever fluid is tobe moved considerable distances and against relatively high headpressures in order to reach a point of delivery and consumption.

Another important object of the invention may be found in the provisionof a simple and inexpensive fluid pump mcluding a pressurized fluidreservoir for receiving fluid during each pumping stroke and forassisting in the delivery of reservoir fluid with each suction stroke,and means both in fluid flow and hydraulic operating relation therewithfor effecting a predetermined cyclic operation of the pump in itspumping and suction strokes such as will initiate a flow of fluid towardthe delivery line under a materially reduced head pressure, and suchthat the full effect and advantage may be had of the pressure in thefluid reservoir for assisting the lifting of fluid from a low level to ahigher level.

Other objects of the invention reside in the arrangement of anhydraulically actuated pump of the reciprocatory and fluid cyclingcharacter, and in the construction, form, arrangement and operatingfeatures of the various parts and components of the fluid pump assembly.

In its broad aspects, the preferred form and arrangement which the fluidpump may have will be understood to include a fluid suction unito'peratively related with a fluid displacement responsive unit such thatthe actuation of the latter unit will effect a desired operatingresponse in the fluid suction unit to move fluid from its source into apressurized fluid reservoir and transfer system connected in fluiddelivery relation with the responsive unit. The above noted units andfluid reservoir may be assembled as a composite member of the pump andare suitably housed and arranged for location at or closely adjacent tothe source of fluid to be pumped. In operative association with thiscomposite member of the pump, there is arranged at an elevated positionrelative thereto, for example at the ground level or top of a well orother source of fluid, a power operated hydraulic unit which is arrangedto open and closea fluid delivery line opening therefrom and to regulatethe displacement of fluid toward the responsive unit through aconnecting fluid line, as well as the reverse movement or flow of fluidfrom the pressurized fluid reservoir through the responsive unit and theconnecting fluid line to the ultimate discharge therof from the deliveryline at the hydraulic unit. The operation of the hydraulic unit isconstrained to movement in a predetermined cyclic manner by mechanicalcycling means of a type and character developing a relatively uniform orprogressive drive for a portion of its operating cycle, a rapid orrelatively quick reversal of this drive followed by a period in whichthe hydraulic unit is inactive. or nonoperative.

According to this preferred arrangement, a volume of fluid initiallyfllling the hydraulic unit and the fluid line leading therefrom to theresponsive unit of the composite pumping member is displaced by thehydraulic unit, during the period of uniform drive operation of themechanical means, into the responsive unit and is by this latter unittranslated into operation of the suction unit in a direction to movefluid into the fluid reservoir where it is accumulated under a pressureproportional to the volume of fluid so accumulated. This action isfollowed by a rapid reversal of the hydraulic unit such as will cause adrop in pressure of the initially displaced fluid and as a result, causethe fluid in the responsive unit to flow in a reverse direction. Thefluid pressure drop at the latter unit is therefore accom. panied by aflow of accumulated fluid from the pressurized reservoir into andthrough the responsive unit and to the hydraulic unit for delivery atthe discharge line leading therefrom. The period of inoperativeness ofthe hydraulic unit is timed to permit a full reverse fluid flow towardthe discharge line and thereby effective utilization of the reservoirpressure in assisting flui'd flow therefrom. As this reverse flow offluid from the low level location of the pumping member to the dischargeline at the high level location of the hydraulic unit is retarded by thegravitational effect on the fluid column, restoring means operatlvelyconnected with the responsive unit and the suction pumping unit becomesoperative to re-set the responsive unit for subsequent cyclic operationand to move the pumping unit in its fluid suction In the accompanyingdrawing:

Figure 1 is a schematic arrangement of the fluid pump herein preferred,and in which the several units and operating parts have been shown in,sectional elevation, and Figure 2 is a schematic plan view of amultiple arrangement of composite pumping members adapted to deliverfluid to a common line connected with the hydraulic unit of the system.

With more speciflc reference to the-drawing, the present invention, asdisclosed in Figure 1, comprises .the composite pumping member A adaptedto be located at a low level relative to the hydraulic unit B and themechanical operating means C. It will be observed that the fluid pumphas been illustrated in a generally schematic arrangement such as willenable 'a complete understanding of the principles of its operation.However, the invention may be carried out with means other than thatspecifically disclosed herein, and it is the intention to include allsuch equivalent arrangements within the scope hereof.

In Figure 1, the hydraulic unit B includes the cylinder I suitablysupported by legs 2 from a base structure 3, and aplston 4 movable inthe cylinder between the inactive or at rest position shown and theopposite limit of the cylinder chamber. The cylinder I is provided witha fluid outlet port Ii which isopened and closed by the piston 4, andwhich port leads to the fluid delivery line 6 through a suitable ballcheck valve 1. As will appear presently, the cylinder I is placed influid communication with the member A of the pump through line 8. Aby-pass line 3 is including a pressure responsive safety valve I isprovided between line 8 and the delivery line 6.

The hydraulic unit B is operated in a predetermined cyclic. manner bythe mechanical drive means C which is operatively connected through rodI2 with the piston 4. In its preferred. construction, means C includes ashaft I3 rotatably carried-in spaced bearing stands I4 on base 3, adrive element or gear I6 fixed on the shaft in position to be connectedwith a motor or'other prime mover (not shown), a cycling drive cam I6also fixed on the shaft to engage a follower roller element I'I onpiston rod I2, and a retracting or return spring element I8 which isfixed at one end to a base stand I9 and at the opposite end to a yokeconnector piece 20. This yoke is, in turn, attached to the piston rod I2and through the spring I8 normally urges the piston 4 to the positionshown in Figure 1. The cycling drive cam I6 is peripherally shaped toprovide an arcuate portion 2| of constant radius, a progressively risingsurface 22 of substantial arcuate extent, and a radially directedcut-off edge 23. It will thus appear that for counterclockwise rotationof the cycling cam I6 the piston 4 will remain at rest during the periodof contact of roller H on the constant radius cam surface 2 I. This isthe so-called dead spot of the cam I6 as the piston 4 will have nomotion in cylinder I and consequently will remain at rest for theduration of cam rotation through this arcuate extent. Continued camrotation will bring the progressively rising surface 22 into drivingcontact with the rod follower I! for displacing the piston 4 to theopposite limit of its strokel When the cut-off edge 23 is rotated pastthe roller II, the retracting spring I8 will immediately act to returnthe piston 4 to the position shown in correspondingly rapid reversal offluid flow in line 8 to cause a fluid delivery impulse past the checkvalve I and outwardly through line 6 leading from cylinder I.

The composite pumping member A which is responsive to the cyclicoperation of the hydraulic unit Bis seen to include: a fluiddisplacement responsive unit comprised of the cylinder, 24 whichcommunicates with line 8 at' its closed' end, and a piston 26 movabletherein from and to this closed end; and a. fluid suction unit alsocomprised of a cylinder 26 having the fluid suction line 21 connected atits closed end through a line check valve 28, and a piston 23 movable inthe cylinder from and to this closed end. These last described units aresuitably carried on a base structure 30 in a generally tandem or axiallyaligned relation such that a single rod 3| may be used to couple thepistons 25 and 29 for simultaneous movement. These pistons 26 and 29 arenormally urged to one limit of their stroke by the provision of one ormore spring elements 32 (two being shown here) each of which may beadjustably secured by Figure 1. When this occurs the sudden and rapidreverse piston motion effects a desired reduction in the fluid pressureof line 8 such as will impart a threaded elements 33 to the cylinder 24and attached to the rear side of the piston 29, in the manner indicated.In the example of Figure 1, the springs 32 act to retain the piston 29at the end of its suction stroke thereby charging cylinder 26 with avolume of fluid drawn in through the suctlonline 21 and past the 'checkvalve 28. At the same. time, piston 26 is at the inner or closed end ofthe cylinder 24 and in position to respond to the inflow fluid from line8 under the hydraulic driving impulse imparted thereto by the piston 4of the hydraulic unit B.

Before describing the pump operation, it will be noted that thecomposite pumping member A includes a pressurized fluid reservoirarranged in uni-directional flow communication between 24 and 26. In apreferred form, this means comprises an air bell or dome 35 having adual-purpose air valve 36 in the top surface which is controlled by thefloat 31. The float 31 has a predetermined degree of rise and fallbefore actuating the valve 36. The valve 36 communicates with theatmosphere through an open end line 38, so that during periods of excesshigh liquid level in the air bell or dome 35, the float 31 rises andoperates the valve 36, allowing'air to be drawn into the cylinder 26through the uni-directional line 39, which air is then forced into theair bell or dome 35, through the line 40, thus lowering the excessliquid level. This is to compensate for the absorption of air by theliquids. When the liquid level falls below the desired level in the airbell or dome 35, the float 31 descends and operates the valve 36, sothat air will escape from the dome 35, thus allowing the liquid level torise to the desired height. This is for the purpose of bleeding off suchair therefrom as is normally entrained with the incoming volume ofsuction fluid. The air dome 35 receives a quantity of pumped fluid fromthe cylinder 26 through the feed line 40, and this fluid is preventedfrom reverse flow by means of the check valve 4i located close to theline connection at the cylinder 26. The liquid to be expelled from thedome 35 under the impulse of the air trapped therein, flows through anoutlet line 42 and into the cylinder 24 past the check valve 43 adjacentthereto.

Operation of the pump is as follows: Rotation of the cyclic drive cam I6causes displacement of piston 4 in a direction first to close the outletport 5 in cylinder I and then to move or displace a volume of'fluidthrough line 8 and into cylinder 2d of the responsive unit. This volumeof fluid is initially admitted to the pump for the purpose of primingthe same, but once operation has completed the first full cycle. thepump will then continue working automatically. The hydraulic action ofthis fluid is to force piston 25 outwardly against the return springs 32and to drive the pumping piston 29 inwardly of its cyl inder 26, therebyforcing fluid into reservoir means through line at by the directingaction of valves 28 and M. The air valve 38 will close upon rise of thefloat actuated needle 3? and air in the top zone of the dome 35 will becompressed. However, no fluid can pass through line d2 into the cylinder26 as the hydraulic pressure in this latter cylinder will maintain valve43 closed. The above cycle occurs during the time cam surface 22 isoperative on the piston rod i2. When the cut-off cam edge 23 moves pastthe rod follower ll, return springs I8 will immediately and rapidlyreturn the piston t to the position shown in Figure 1, thus openingoutletport 5 and reducing the pressure in line 8 to a sub-atmosphericvalue. Consequently, the hydraulic column in line 8 is reversed in itsdirection of flow and the fluid in 6 2d. Where the pumping member A islocated below or at a lower level relative to the unit B,

' the inter-connecting line 8 should be arranged the pressurizedreservoir will be released by openaccomplished by a material dropinpressure at flrst, but as such pressure does begin to fall off, piston25 will be enabled to return to its starting position (Figure 1) underthe forcing action of springs 32. Thus the piston 25 will for a timematerially aid in the upward flow of fluid for eventual delivery in line6.

During the period when the fluid is flowing outwardly of the reservoirand upwardly in line 8, the cycling cam I6 is moving in its "dead spotand piston I is at rest. This latter condition of cam operation willpermit the composite pumping member A to attain its original pistonsetting and efl'ect a pumping suction stroke of piston 29 such as willrecharge cylinder 26 for each subsequent cycle of operation. Thus thecycling cam eflects a period of hydraulic actuation of the pumpingmember A through unit B, a sudden and rapid period of reverse fluid flowaccompanied by a quiescent or "dead spot" period to enable a maximumdischarge from line 8 of the fluid in the pressurized reservoir system35, 40 and I2, and a fluid charging or suction stroke of the member A.

Figure 2 illustrates a multiplearrangement of pumping members A, eachof. which is conto be free of reverse bends such as would cause an airlock. Moreover, the return or retracting springs 32 for displacing thepistons 25 and 29 should be tensioned according to each installation soas to ofiset the weight of fluid in the line 8 (Figure 1) or lines {35and 36 (Figure 2). When constructed in the manner described and with dueregard to accepted hydraulic practices, it is believed that this fluidpump will have an advantageous emciency comparable to other pumpscapable of performing the same work. It will also appear that the sizeand pumping capacity may be varied over a wide range and that the pumpcan be applied to many and varied uses, especially where the fluid to bepumped has both distance and head.

The above description has referred to a preferred construction ofhydraulically actuated fluid pump, but it should be understood that thescope of the invention is intended to include equivalent arrangementsand variants such as will come within the spirit of the appended claim.

I claim:

In a fluid pump, the combination of a fluid suction unit having acylinder provided with valve controlled fluid inlet and outletconnections and a piston movable in the cylinder alternately for suckingfluid through the inlet connection and pumping the same through theoutlet connection, a fluid responsive unit having a cylinder providedwith a valve controlled fluid inlet connection and a piston movable inthe cylinder, means operatively connecting said pistons for simultaneousmovement, resilient means connected to one of said pistonsfor urging the40 piston of said suction unit to the limit of its fluid structed in themanner described in connection with Figure 1 and the like parts areindicated by similar reference numbers. In this arrangement each of themembers A is connected'by a branch line 45 with a common flow line 48which leads upwardly to a common hydraulic unit, such as the.

one shown and described at B in Figure 1. The

operation of the multiple pumping assembly conterms to that alreadynoted and therefore no es turther discussion is believed necessary.

' In constructing the present fluid pump..thcre are certain relations ofparts which. if observed. will contribute to the success of itsoperation. It

is preferred that the cylinder 20 be somewhat larger than the cylinder24. and that the efl'ective volume of the cylinder i of unit B besubstantill y equal to the volume of cylinder 24 (Figure 1), or in themultiple pump of Figure 2 equal suction movement, a fluid reservoirconnected between the respective fluid outlet and inlet connections ofsaid flrst and second mentioned cylinders, a float controlled airadmission valve in said reservoir which is operative to retain airtherein such as will pressurize the reservoir fluid pumped thereinto bysaid suction unit, an hydraulic actuating unit connected in fluid flowrelation with the cylinder'of said responsive unit, said hydraulic unitbeing provided with a fluid delivery line, and means for actuating saidhydraulic unit alternately to eflect hydraulic movement of the piston insaid responsive unit against said resil ient means and in a direction topump fluid into said reservoir, and to eflect a rapid reversal ofhydraulic actuation thereo! whereby the fluid in said reservoir issuddenly released and efl'ectively forced under reservoir pressuretoward said bydraulic unit for flow through said delivery line.

" ALVIN F. O'HARAH.

REFERENCES CITED The following references are of'record in the flle ofthis patent:

UNITED STATES PATENTS Number Name Date 1,018,768 Pagliuchi Feb. 6, 1911,784,706 Phillips Dec. 9, 1930 2,008,572 Hermann July 2, 1935 I romanre'mn'rs Number Country Date I 600,280 France Feb. 8, 1926 to thecombined volume of all of the cylinders 70

